Apparatus for evaporating sugar and the like.



J. T. DAVIS.

APPARATUS FOR EVAPOKRAHNG SUGAR AND THE LIKE.

APPLlcATmN f|LEn1uLY1x,1916.

Patented. Apr. 23, 1918.

APPARATUS FOR EVAPOBATING SUGAR AND THE LIKE.

Specication of Letters Patent.

Patenten apr., as, rais,

Application led July 11, 1916. Serial No. 108,564.

To all 'whom t may concern: l

Be it known that l, JOHN T. DAVIS. a citizen of the United States, residing at Alameda, in the county of Alameda and State ofv California, have invented new and useful Improvements in Apparatus for Evaporating Sugar and the like, of which the following is a specification.

The present invention relates to an apparatus for evaporating, and especially for evaporating sugar solution.

An objection to the system of evaporating by vacuum pans is that the quantity of sugar in thesolution is constantly changing, the effect of which is to correspondingly vary the rate of evaporation and other conditions of treatment. One object of the present invention is to provide an apparatus byV means of which the rate of supply of sugar solution will be uniform, as will also be the supply of heat, whereby the rate of evaporation of the sugar solution will also be uniform, and the process can be carried on continuously under absolutely uniform conditions. i

A further object of the invention is to so evaporate the solution as to avoid injury by heat to the solid contents, such as sugar in a sugar solution or the casein of milk.

such injury consisting of imparting a burnt flavor to the milk or color to the sugar.

A further object is to provide an apparatus whereby the heat necessary to producey theV evaporation will be applied toa small body of the liquid for a short time only, and

lafter'said body has been sufficiently evaporated it will be immediately rremoved from the influence of the heat, as contrasted with prior methods in which it has been found necessary to apply heat for a long period to a large body of liquid. lt has been found that such long` continued heat was a serious detriment `to the crystallizing property of the sugar. But the only remedy that has heretofore been devised has been to lower the temperature of the applied heat by the provision of the vacuum pan. `While this was a valuable improvement it remedied the evil only to a limited extent. My invention,

on the other hand, contemplates the exposure of the solid contents to a heated surface for a short period only. l accomplish this object by causing the liquid to flow automatically in a thin film over a surface sufciently heatedV to just evaporate the water without unduly heatingthe solids, and l also provide means for immediately removing Y the vapor. from the residual liquid.

A further object of the invention is to provide an apparatus by means of which the sugar solution, when it is beginningto be in a condition for crystallization, will be constantly agitated, while being further evaporated, whereby the crystals that are formed will increase in size by aggregation. i

In the accompanying' drawing, Figure 1 is a transverse section on the line 1-1 of Fig. 2; Fig. 2 is a longitudinal section on the line 2 2 of Fig. l.

Referring to the drawing, 1 indicates a vapor'chamberin which are'suitably supported inverted conical plates 2, here shown as two in number, said plates forming the inner and upper surfaces of conical steam chambers 3. IThe top circular walls 4: of said steam chambers form the bottoms of circular solution chambers 6, through the outer walls Z of which sugar solution, or

other liquid to be evaporated, is fed by branch pipes 8 from a main supply pipe 9., The inner wall 41l of each sugar solution chamber is `conical and approaches very closely to the upper surface of the corresponding conical plate 2, so that the sugar solution can escape through the very narrow opening' 12, about one-sixteenth of an inch in width, between said wall 11 and the plate 2. The sugar solution flowing in a thin film on the conical plates 2, which are heated by the steam in the steam chambers 3, parts with its vapor, until, when arriving at the bottom of the conical plate, it is of a gravity of about 33 Baume. The sugar solution then falls into the uppermost of a Vvertical series of troughs 13, in whichy there are longitudinal screw conveyers 14, on shafts 16, rotating` in bearings 17, and passing through stuliing boxes 18, and carrying on their ends, extending through one end Vof the vapor i strains anni orio, N

chamber. gear wheels 19 meshing with each other. The lowermost shaft carries fast and loose pulleys 2l, by the former of which all of said shafts can be rotated.

The liquid sugar falling into the uppermost of the troughs 13 is moved longitudinally by the screw conveyer 14 therein until it reaches one end thereof when it drops by a Apipe 22 into the next lower trough, and is then moved by the screw conveyer in said trough in the opposite direction, and then falls through a pipe 23 into `a lower trough and is lagain moved in the opposite direction by the screw conveyer therein. When Vmoving in each ont these ytroughs the sugar y rises from the troughs and the sugar solu- Vso tion becomes more and more concentrated. When it arrives at the discharge end of the lowermost trough, it falls through openings 26 ina :gear wheel 27 on to a vertical screw conveyer .28 on a shaft 29, rotatablein a vertical deliverytube 30, surrounded by a steam jacket 31, said gear wheel meshing with a-gearwheel 32 on the lowermost screw conveyer shaft 14. By meansY of said .vertical screw conveyer 28, -itl is conveyed into a chamber 83, from' which it can be removed `trom-timeto timea'sirequired. So much of the vapor'has been evaporated from the sugar solution that. itis now ready for crystallization.

Thefvapor rising from the conical plates 9.', from the troughs 13 and from' the vertical tube 80 iscondensed by means of 'a water spray supplied` @ont aspraying device 3-1- located in the bottom of a water receptacle 36, said* water spray, and the water condensed from thevapor, fallingdown a verticalrpipe? provided at the bottom with a v`liquid'seal 38..- The condensation of the vapor by means of the water spray produces a vacuum' in the upper part of the vacuum chamber,` thus causing vthe vapor to flow quicklyy from theplace where it is generated, so thatr fresh vapor may beY formed thereat. 39; indicatesl a pipe for supplying steam to the steam jackets, and .1.0 a pipe for drawing oli the water condensed therefrom. g

Itl isl tobe observed that, it a suction pump be employed toV produce al vacuum in thevapor chamber, then the delivery tube -Ileedonly entendv but a few Vfeet below the lowermost trough, butk if the operation is conducted without the pump, then the delivery tube should be thirty-four 'feet long and extend to the level'of the water seal, so that thedeliverytube and water pipe may have thesame barometric `pressure,ithe stirring apparatus-'extending to the bottom of the de- 'V i livery. tube.

I.claim:-

1. In an; evaporator, a conical plate, a chamber belowV saidV plate'and/ of which the plate forms the upper side, means for supplying steam to said chamber, andan annular. chamber-on. the rtop of saidconical plate `for containing the liquid to be evaporated andfhaving a wall levtending adjacent'tosaid Y conical plate to form .therewith al narrow annularloutlet for said liquid.4

'2a In an evaporator, thecombination lo'fa vaporwchamber, a'conical plate therein, a

steam.V chamber mmediatelyf beneath said Y plate, and of `which said plate forms the vapor chamber, a conical plate therein, a

steam chamber immediately beneath said plate, and 'of which said plate forms the upper side, an annular chamber locatedf at the top of said conical plate for containing the liquid to be evaporated and :having a discharge'V outletfor discharging the-liquidi on the top Vof said plate, a trough'. into.which the; liquid is discharged from saidt conical plate, a conveyer in said trough, a steam chamber; onfthe under side of said-` trough, means. for supplyingy steamto said steam chambers, and means for constantly'removling the vapor generated 4i. Inan evaporator, the combination ot'a vapor chamber, a conical' plate therein,l a steam chamber immediately beneath said plate, and of which said plateforms the upper side, an annular chamber locatedv at the top'of said conical plate for containing theliquid to be evaporated and having a discharge outlet for discharging the-liquid on the top of said plate, a trough into which the liquid is discharged from saidK conical plate, a conveyer in said trough, a1 steam chamber on the under side of said trough, meansV for supplyingv steam to said steam chambers, and a water spray. for continuously-` condensing the vapor generated.

5; In an evaporator, the combination of a vapor chamber, a conical plate therein, a steam chamberv immediately, beneath said plate, andotwhich said plate forms-the uppery side, an annular chamber located at the top of said conical'plate fork containing the liquid: toAbe evaporated and havingV a discharge outlet for discharging the-fliquid on the top-of; said plate, atrough into `which the liquid is discharged from said conical plate, a. conveyer in said trough, aiv steam chamber on the under sideof.' said trough, means for. supplying steam tosaid steam chambers, a water spray for continuously condensing the vapor generated, a; tube through which the spray watery and; condensed water fall, and a water sealat the bottom of said tube.

6.' Inan evaporator, the combination of'a vapor chamber, a\conical plate therein, a steam chamber immediately beneathl said plate, andfof which said plate formsthe upper side, anannular `chamber located at theftopot saidfconical Aplate -or containing recava? the liquid to beevaporated, and having a discharge outlet for on the top of said plate, a trough into which the liquid is discharged from said conical 5 plate, a conveyer in said trough, a steam chamber on the under side of said trough, a vertical tube, a conveyer therein on to Which discharging the liquid the material conveyed by the rst conveyer drops, a steam chamber around said tube, and means for operating said conveyerssi- 10 multaneously, and means fo supplying steam to said steam chambers.

JOHN T. DAVIS.

@omen or' tibia patent may 'be obtained'for ve cents cach, by addressing the "Gommiseioner otwutcmtm,

Washington, D. G. 1 v 

